Merge branch 'master' into 3.0

Conflicts:
	errai-bus/src/main/java/org/jboss/errai/bus/server/io/BufferHelper.java
fix to deadlocking problem on machines with 2 cores
support clientId as a URL attribute in StandardAsyncServlet
fix to SSE implementation
make sure GWTUtil hooks into the central CacheUtil so it is properly cleaned
defensive check. do not poll if no queue.
New test for relative template paths that use "../"